using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using System.Text;
using static System.Console;
using static System.Math;

namespace CP
{
    class Atria
    {
        static void Main(string[] args)
        {
            string s = ReadLine();
            var sb = new StringBuilder();
            for (int i = 0; i < s.Length; i++)
            {
                if (char.IsUpper(s[i]))
                {
                    sb.Append(char.ToLower(s[i]));
                }
                else
                {
                    sb.Append(char.ToUpper(s[i]));
                }
            }
            WriteLine(sb.ToString());

        }
    }
}